Question

The length and breadth of a rectangular field are in the ratio 9:5 . If the area of the field is 14580 square metre, find the cost of surrounding the field with a fence at the rate of ₹ 3.25 per metre ?

Answer 1

Area of rectangle =lb (sq. units)

Here L=9x and B=5x ,where x be the constant

ACCORDING TO THE QUESTION,

9x × 5x = 14580

45x^2 = 14580

x^2 = 324

x = 18

SO THE SIDES ARE 9 × 18 = 162m

5 × 18 = 90 m

COST OF FENCING = 3.25 × perimeter

= 3.25 × 2( l+b)

= 3.25 × 504

= 1638

THEREFORE COST OF FENCING IS RS. 1638.

Answer 2

Let the length of rectangle be 9x and its breadth be 5x

So,

Area = l × b

⇒ 14580 = 9x × 5x

45x2 = 14580

x2 = 14580/45 = 324

x = √324

x = 18

Hence,

Length = 9 × 18 = 162 m and Breadth = 5 × 18 = 90 m

Now, Perimeter = 2(l + b)

= 2 (162 + 90) = 2(252)

= 504 m.

Therefore, cost for fencing the surrounding 504 m at the rate of ₹3.25 per metre = ₹(504 × 3.25) = ₹1638

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